1. Field of the Invention
The present invention relates to an image forming apparatus employing the electrophotographic method, such as a copier, a printer, a facsimile machine, or a multifunctional peripheral having the aforementioned functions, for controlling the operation of conveying of a sheet which is a recording medium, when a conveyance failure of the sheet occurs in the image forming apparatus.
2. Description of the Related Art
Conventional image forming apparatuses such as copiers and printers have the following function. That is, when paper jam occurs, the sheet is conveyed to a location to avoid all boundary parts between units that can be pulled out, so that the sheet does not extend over plural units, thereby preventing the sheet from tearing into pieces (see, for example, patent document 1).
Patent document 1: Japanese Laid-Open Patent Application No. H2-163244
However, in the invention disclosed in the above conventional reference, the sheets are evacuated one by one. Thus, according to the conventional reference, every time a conveyance failure occurs, the sheets other than the sheet for which the conveyance failure has occurred are dispersed into different locations in the sheet conveying path. Accordingly, every time a conveyance failure occurs, the operator is required to remove the sheets from different locations. Therefore, the conventional reference requires complicated operations of removing the sheets from different locations, which leads to time-consuming operations in order to resolve the paper jam.
If in the invention disclosed in the conventional reference, every time a conveyance failure occurs, the sheets are prevented from dispersing to different locations so that the operator can resolve the paper jam by removing sheets from only a particular location, the following problem occurs. That is, conveyance control operations need to be performed to convey the sheets to the particular location, which leads to complicated operations in the apparatus.
Particularly, to respond to increasing demands for mass production in recent years and continuing, the sheet conveyance speed is increasing. Furthermore, image forming apparatuses are being configured to retain multiple sheets in an attempt to increase the sheet conveyance speed. With such a configuration, when conveyance failure occurs in the image forming apparatus, downtime will be required for removing sheets. During the downtime, the image forming apparatus is not capable of forming images on sheets. Accordingly, it is necessary to minimize the time required for removing sheets from an image forming apparatus.
Incidentally, in an image forming apparatus that is capable of mass production, the paper eject speed is, for example, approximately 90 sheets per minute, and the interval between sheets is approximately less than or equal to 70 mm.